Vehicles such as electric vehicles (EVs) and plug in hybrid vehicle (PHVs) are equipped with a rechargeable battery, which is a power storage device that stores power fed to a drive motor. For example, the rechargeable battery includes an electrode assembly having a positive electrode and a negative electrode, and a case that houses the electrode assembly. An insulating sheet that covers the electrode assembly to insulate the electrode assembly from the case may be provided. In this case, the insulating sheet may be shaped like a spread polygon in advance and then, assembled such that adjacent sides are butted to house the electrode assembly. Refer to Patent Document 1, for example.